This invention relates to measuring the radiation axial ratio of any antenna instantaneously without the use of a revolving linearly polarized sampling antenna.
At present, the usual methods employed in measuring the radiation axial ratio of antennas is to employ a linearly polarized antenna which can rotate about its propagation axis. Although this method is extensively employed, difficulties are often encountered because of the variation of reflected energy with rotation, particularly on outdoor ranges, which results in unreliable measurements. Further inaccuracies also come about in the narrow beam rotating sampling antennas, which are employed on long ranges where high grain is required, due to the lobing effects which come about from misaligned antenna beams or from angular offsets of a rotating feed in a dish.